Association of a single nucleotide polymorphic variation in the human chromosome 19q13.3 with drug responses in the NCI60 cell lines

Pan-cancer integrated bioinformatic analysis of RNA polymerase subunits reveal RNA Pol I member CD3EAP regulates cell growth by modulating autophagy

Transcription is a crucial stage in gene expression. An integrated study of 34 RNA polymerase subunits (RNAPS) in the six most frequent cancer types identified several genetic and epigenetic modification. We discovered nine mutant RNAPS with a mutation frequency of more than 1% in at least one tumor type. POLR2K and POLR2H were found to be amplified and overexpressed, whereas POLR3D was deleted and downregulated. Multiple RNAPS were also observed to be regulated by variations in promoter methylation. 5-Aza-2-deoxycytidine mediated re-expression in cell lines verified methylation-driven inhibition of POLR2F and POLR2L expression in BRCA and NSCLC, respectively. Next, we showed that CD3EAP, a Pol I subunit, was overexpressed in all cancer types and was associated with worst survival in breast, liver, lung, and prostate cancers. The knockdown studies showed that CD3EAP is required for cell proliferation and induces autophagy but not apoptosis. Furthermore, autophagy inhibition rescued the cell proliferation in CD3EAP knockdown cells. CD3EAP expression correlated with S and G2 phase cell cycle regulators, and CD3EAP knockdown inhibited the expression of S and G2 CDK/cyclins. We also identified POLR2D, an RNA pol II subunit, as a commonly overexpressed and prognostic gene in multiple cancers. POLR2D knockdown also decreased cell proliferation. POLR2D is related to the transcription of just a subset of RNA POL II transcribe genes, indicating a distinct role. Taken together, we have shown the genetic and epigenetic regulation of RNAPS genes in most common tumors. We have also demonstrated the cancer-specific function of CD3EAP and POLR2D genes.

Association of PPP1R13L and CD3EAP polymorphisms with risk and survival of non-small cell lung cancer in Chinese non-smoking females

PPP1R13L and CD3EAP were confirmed to play important roles in transcription and apoptosis. SNPs in PPP1R13L and CD3EAP may be associated with lung cancer risk and survival. This study investigated the association of PPP1R13L rs1005165 and CD3EAP rs967591 with non-small cell lung cancer (NSCLC) risk and survival in Chinese non-smoking females. 442 NSCLC cases and 480 cancer-free controls were conducted in the case-control study, and 283 cases were in cohort study. Genotype was determined by Taqman real-time PCR. The statistical analyses were performed by SPSS 22.0 software. We found that rs1005165 and rs967591 were significantly associated with NSCLC risk in Chinese non-smoking females. For rs1005165, compared with homozygous wild CC genotype, carriers of CT or TT genotype had lower risk of NSCLC (adjusted ORs were 0.675 and 0.713, 95% CI were 0.461-0.988 and 0.525-0.968, respectively), adjusted OR for dominant model was 0.702, 95% CI was 0.526-0.937. For rs967591, AA genotype (adjusted OR = 0.721, 95% CI = 0.532-0.978) and at least one A allele (GA+AA) (adjusted OR = 0.716, 95% CI = 0.536-0.956) were significantly correlated with lower risk of NSCLC, compared with GG genotype. But we didn't find correlation between the two SNPs and survival time in Chinese non-smoking NSCLC females. In general, we found PPP1R13L rs1005165 and CD3EAP rs967591 might be associated with lower NSCLC risk in Chinese non-smoking females, but no significant relationship was found with NSCLC survival.

Distinguishing between cancer cell differentiation and resistance induced by all-trans retinoic acid using transcriptional profiles and functional pathway analysis

All-trans retinoic acid (ATRA) induces differentiation in various cell types and has been investigated extensively for its effective use in cancer prevention and treatment. Relapsed or refractory disease that is resistant to ATRA is a clinically significant problem. To identify the molecular mechanism that bridges ATRA differentiation and resistance in cancer, we selected the multidrug-resistant leukemia cell line HL-60[R] by exposing it to ATRA, followed by sequential increases of one-half log concentration. A cytotoxicity analysis revealed that HL-60[R] cells were highly resistant to ATRA, doxorubicin, and etoposide. A comparative genome hybridization analysis of HL-60[R] cells identified gains of 4q34, 9q12, and 19q13 and a loss of Yq12 compared with in the parental HL-60 cell line. Transcriptional profiles and functional pathway analyses further demonstrated that 7 genes (FEN1, RFC5, EXO1, XRCC5, PARP1, POLR2F, and GTF2H3) that were relatively up-regulated in HL-60[R] cells and repressed in cells with ATRA-induced differentiation were related to mismatch repair in eukaryotes, DNA double-strand break repair, and nucleotide excision repair pathways. Our results suggest that transcriptional time series profiles and a functional pathway analysis of drug resistance and ATRA-induced cell differentiation will be useful for identifying promyelocytic leukemia patients who are eligible for new therapeutic strategies.